This application claims the benefit of co-pending German Patent Application No. 100 01 303.1 entitled xe2x80x9cSpulmaschinexe2x80x9d, filed on Jan. 14, 2000.
The present invention generally relates to a winding machine including a yarn traversing apparatus. Preferably, the winding machine is an apparatus for winding up continuously arriving yarn on bobbins. However, the invention is also applicable to other types of winding machines. The present invention also relates to a yarn traversing apparatus.
A winding machine is known from German patent application No. 195 36 761 A1. The winding machine includes a yarn traversing apparatus including a housing. A drivable reversing screw thread shaft is supported inside the housing to be rotatable therein. The reversing screw thread shaft includes an endless screw thread groove. A traversing yarn guide includes a body, a shuttle engaging the groove of the shaft and a yarn guide. The traversing yarn guide is driven by the groove to move back and forth in an axial direction. The housing includes an elongated opening through which the yarn guide of the traversing yarn guide protrudes out of the housing. The winding machine further includes two guide rods for radially guiding the traversing yarn guide. For this purpose, the two guide rods are arranged parallel with respect to one another, and the body of the traversing yarn guide is connected to the parallel guide rods. The body includes two round bores through which the cylindrical guide rods extend. The guide rods extend over the entire length of the screw thread shaft and over the region of the screw thread shaft in which the endless screw thread groove is located, respectively. To prevent the traversing yarn guide from getting jammed at the guide rods, the two guide rods have to be assembled to be exactly parallel. The separate guide rods have to be manufactured, hardened and ground. It is a very important to exactly align the two guide rods during assembly.
Another winding machine is known from German patent No. 196 42 473 C1. The winding machine includes a yarn traversing apparatus including a housing, a reversing screw thread shaft and a traversing yarn guide. Two parallel guide bars are located at the housing in a way that they contact the body of the traversing yarn guide to guide it in a radial direction. The guide bars have to be separately manufactured, hardened and ground in the contact region to the body of the traversing yarn guide. Then, the guide bars have to be screwed to the housing. For this connection, a respective milled, plain surface is required at the housing. The milled surface causes the housing to be structurally weakened. The process of manufacturing, hardening and grinding the guide bars is rather complex and expensive.
The present invention relates to winding machine. The winding machine includes a yarn traversing apparatus including a housing having an elongated opening. A reversing screw thread shaft has an outer surface, it is rotatably supported in the housing and it includes an endless screw thread groove. A traversing yarn guide includes a body, a shuttle being designed and arranged to engage the endless screw thread groove, a yarn guide and a guide bush having an inner surface. The traversing yarn guide is designed and arranged to be driven by the reversing screw thread shaft to reciprocate in an axial direction. The yarn guide is designed and arranged to project out of the elongated opening of the housing. The inner surface of the guide bush is designed and arranged to at least partially surround the outer surface of the reversing screw thread shaft.
The present invention also relates to a yarn traversing apparatus. The yarn traversing apparatus includes a housing having an elongated opening. A reversing screw thread shaft has an outer surface, it is rotatably supported in the housing and it includes an endless screw thread groove. A traversing yarn guide includes a body, a shuttle being designed and arranged to engage the endless screw thread groove, a yarn guide and a guide bush having an inner surface. The traversing yarn guide is designed and arranged to be driven by the reversing screw thread shaft to reciprocate in an axial direction. The yarn guide is designed and arranged to project out of the elongated opening of the housing. The inner surface of the guide bush is designed and arranged to at least partially surround the outer surface of the reversing screw thread shaft.
With the novel winding machine and the novel yarn traversing apparatus, the traversing yarn guide is guided and supported in a radial direction in the inside of the housing and directly at the reversing screw thread shaft, but no longer outside of the housing and in the region of the elongated opening of the housing, as it is known from the prior art. This novel way of supporting the traversing yarn guide is rather cheap, and it may be are realized with a rather little number of components.
The outer circumferential surface of the reversing screw thread shaft is at least partially surrounded and enclosed by the inner circumferential surface of the guide bush of the traversing yarn guide. The guide bush at least surrounds the reversing screw thread shaft by more than 180 degrees to secure and support the traversing yarn guide in a radial direction. With the present invention, additional, separate guide elements, as guide rods or guide bars, are not required. The number of structural elements of the winding machine and of the yarn traversing apparatus is advantageously reduced. Since the reversing screw thread shaft usually is already ground for the contact to the shuttle of the traversing yarn guide, no additional operational step is necessary during the manufacture of the shaft to realize the novel function of the radial guidance of the traversing yarn guide. The manufacture of the housing of the yarn traversing apparatus is advantageously simplified since the region of the elongated opening does not have to provide for the radial support of the traversing yarn guide. Since only very little material has to be taken of the housing (compared to the material that has to be taken of the housing in case guide rods will be connected to the housing), the structural stability of the housing is improved. The inner circumferential surface of the guide bush and the outer circumferential surface of the shaft together form a relatively great supporting surface for the traversing yarn guide in a radial direction. Consequently, wear and tear occurring at the traversing yarn guide is reduced.
Preferably, the inner circumferential surface of the guide bush and the outer circumferential surface of the reversing screw thread shaft are ground, and they together form a sliding fit. As it has already been explained, the outer circumferential surface of the reversing screw thread shaft usually is already ground for the contact to the shuttle. Consequently, no additional operational step is necessary. Additionally, the inner surface of the guide bush is ground to realize a precise axial relative movement between the guide bush of the traversing yarn guide and the reversing screw thread shaft. Preferably, the guide bush only extends over a small axial portion of the shaft in a way that the surface of the guide bush that has to be ground is rather small. In this way, the grinding process of the inner circumferential surface of the guide bush takes less time, and it is less expensive.
The guide bush may be designed to be circumferentially closed. This means that the guide bush together with the body of the traversing yarn guide encloses the entire circumference of the reversing screw thread shaft. Such an arrangement has the advantage of very securely guiding the traversing yarn guide on the circumference of the reversing screw thread shaft in a radial direction. Tube material may be easily used for the manufacture of the guide bush. The guide bush and the body of the traversing yarn guide, respectively, include a bore into which the shuttle is being inserted to be freely rotatable in the bore. The shuttle has to be freely rotatable to prevent it from being destroyed when moving through the reverse location of the thread channel of the reversing screw thread shaft.
However, the guide bush may instead be designed to be partially open in a circumferential direction. The guide bush at least has to be closed to an extent preventing it from being removed from the reversing screw thread shaft in a radial direction and guaranteeing the radial support of the traversing yarn guide. This means that the guide bush surrounds the circumference of the shaft by at least a little more than 180 degrees. The partially open design of the guide bush provides for the advantage of the mass and of the weight, respectively, of the guide bush and of the entire traversing yarn guide being reduced. The inner surface of the guide bush of which the quality is improved by grinding is less than the surface in the closed design of the guide bush. In this way, the necessary expenditure for grinding is further reduced. It is also possible to reduce the mass of the guide bush by radial bores or the like.
The reversing screw thread shaft may include a plurality of endless screw thread grooves each being designed and arranged to drive one traversing yarn guide. The screw thread grooves are spaced apart in an axial direction in a way that the traversing yarn guides also moves in an axially spaced apart manner. Depending on the respective mounted position of the traversing yarn guides, they respectively move with respect one another. The traversing yarn guides may be inserted into the screw thread grooves to always move at the same distance with respect to one another. However, the traversing yarn guides may also operated non-equiphase.
The yarn traversing apparatus may include two yarn guides being spaced apart by 180 degrees. Accordingly, the housing includes two elongated openings being spaced apart by 180 degrees. In this way, two yarn guides may be used to simultaneously wind the yarn onto two separate bobbins.
The yarn traversing apparatus may further include a sealing strip being designed and arranged to cover and to protect the elongated opening of the housing. The traversing yarn guide may further include a cover or lid being connected to the body of the traversing yarn guide. The cover and the body are arranged to form a gap between them. The sealing strip is designed and arranged to extend through the gap. In this way, dirt, dust, impurities and especially rubbed-off parts of yarn are prevented from entering the interior of the housing of the yarn traversing apparatus and from reaching the reversing screw thread shaft. Generally, there is the problem with winding machines that the rubbed-off parts of yarn enter the housing of the yarn traversing apparatus through the elongated opening, and they settle on the thread groove of the screw thread shaft.
The rubbed-off parts of yarn bond with grease being located inside the housing for lubricating the screw thread shaft, and the resulting viscous mixture has a negative influence on the movement of the traversing yarn guide. The consumption of energy of the winding machine increases with the friction increasing due to the present impurities. There is the danger of the traversing yarn guide getting caught at the particles of dirt, and consequently getting damaged. For example, such impurities cause a destruction of the shuttle of the traversing yarn guide. The new way of sealing the yarn traversing apparatus effectively prevents impurities from entering the region of the reversing screw thread shaft. The drive of the traversing yarn guide, meaning the reversing screw thread shaft including the groove, is located in the winding region. Consequently, the yarn traversing apparatus has advantageously compact dimensions.
The new way of sealing the yarn traversing apparatus of the winding machine may also be applied without using the new guide bush for radially guiding the traversing yarn guide, and it still provides great advantages. Especially in case the sealing strip with its two ends is fixedly connected to the housing, the sealing strip effectively seals and protects the elongated opening of the housing. For this purpose, the housing in the region of its walls enclosing the elongated opening has a plain, flat surface being produced by milling. Except its region contacting the traversing yarn guide, the sealing strip is supported on this plain surface. In the region of the traversing yarn guide, the sealing strip is being lifted in a direction away from the housing. In this region, the traversing yarn guide itself fulfills the function of covering and sealing the elongated opening of the housing. During the axial movement of the traversing yarn guide, the traversing yarn guide slides along the stationary sealing strip. Thus, a relative movement occurs between the sealing strip and the air gap of the traversing yarn guide. In other words, the traversing yarn guide with its cover moves over the sealing strip.
Two holding-down elements extending in a downward direction towards the elongated sealing element may be arranged at the cover. The holding-down elements serve to hold down the sealing strip outside the region of the traversing yarn guide, and they prevent impurities from penetrating into the interior of the traversing yarn guide and into the region of the reversing screw tread shaft. The sealing strip is designed as one piece, and it has a length approximately corresponding to the length of the elongated opening of the housing. For the dimensioning and the assembly of the sealing strip at the housing, it has to be taken into account that a respective additional length of the sealing strip is required to overcome the radial distance between the supporting surface for the sealing strip and the air gap.
The required length of the sealing strip also depends on its material and on its elasticity. Preferably, the sealing strip is designed as a hardened and ground elongated strip being made of steel. This structure provides for the advantage of the sealing strip having good form stability and low friction at low wear and tear. The sealing strip a may also be made of an appropriate different material, for example, a plastic texture including enclosed fiberglass. It is always desired to attain low friction, little wear and tear, sufficient form stability and sufficient flexibility of the sealing strip. The width of the air gap preferably is slightly less than the thickness of the sealing strip. For example, the thickness of the sealing strip may be approximately 0.5 mm. During the assembly of the sealing strip, the sealing strip is subjected to tension to ensure a complete, flat support and contact of the sealing strip on the housing.
Other features and advantages of the present invention will become apparent to one with skill in the art upon examination of the following drawings and the detailed description. It is intended that all such additional features and advantages be included herein within the scope of the present invention, as defined by the claims.